An electronic-component-mounting line used in production of assembly boards including components mounted thereon is commonly of a general-use type and may be utilized for producing many types of assembly boards. Including a mounting mechanism significantly improved in quality and function, the electronic-component-mounting line accordingly operates in a so-called “continuously-shifting” mode for mounting the components onto different types of bare boards not with a change of its component feeders along the mounting line but with a change of control data.
The continuously-shifting mode is however disadvantageous to an improvement in productivity. The mode, since allowing the component feeders to be fixedly located in the line, may hardly be optimum in the productivity when different types of products are manufactured. It is difficult to appropriately determine which order the different bare boards are put in the line and when the component feeders are changed. Steps of the production can not be evaluated in view of the productivity, and this prevents the productivity from being improved.